There is a video I saw here: http://www.hairdirect.com/video/how-to/detangling.aspx

It is also careful to point out the danger of mixing Ammonia and Bleach. The video states that you should be sure the Ammonia has completely been removed from both your hair system and the sink or tub you are working in.

I don't know if this is exactly what you were looking for but it seems like the way you descibed it this is the method.

Later-
Matthew